The present invention relates to a remote-controlled camera capable of being operated from a distance by the use of infrared light.
There have been widely used remote-controlled methods with which TV sets, audio sets and air conditioning systems can be operated from a distance by the use of infrared light or supersonic waves, and a remote-controlled camera is also available on the market.
In the conventional remote-controlled camera, remote-control signals are transmitted from a remote-control signal transmitter capable of being attached to or detached from a camera body, and when the remote-control signals are received on the camera, a shutter of the camera is released. In order for the remote-control signals to be received surely on the camera, pulse signals are generated repeatedly, thereby, even when the first pulse signal fails to be received, the following or other pulse signal can be received so that an remote-controlled operation may be made surely. (Refer to Japanese Patent Publication Open to Public Inspection No. 28987/1979 and Japanese Patent (Utility model) Publication Open to Public Inspection No. 96439/1982.)
On the other hand, some of the recent AF (automatic focusing) cameras employ an active method wherein a camera irradiates infrared light to a subject and then receives the reflected light from the subject, thereby obtaining the distance to the object (subject distance) through the principle of triangulation. When a camera of this kind is equipped with above-mentioned remote-control system, a remote-control signal transmitter continues transmitting pulses of infrared light even after the camera actions are started by the first pulse of infrared light in the remote-control signals, which may cause fear that such pulses of infrared light may be received by the AF reception unit in a camera. When it happens, the measured value of the subject distance may suffer a distortion, resulting in an inaccurate value.
The first object of the invention devised from the aforesaid viewpoint is to prevent that remote-control signals interfere with an AF reception unit in a remote-controlled camera wherein an active method with infrared light is employed as an AF system.
On the other hand, many of recent cameras are equipped with an AF (automatic focusing) mechanism, and it is possible to focus automatically on the subject which is framed in a frame called an AF frame. However, the AF frame is generally provided in a small space at the center of a viewfinder, and when a subject is out of the AF frame, the camera is focused not on the subject but on the background. Recently, therefore, a camera is equipped with a two-step shutter release button wherein a subject to be focused is first framed in an AF frame and then the subject distance is measured while the shutter release button continues being pressed by one step with the measured results being stored in a camera electrically or mechanically (this is called AF lock), and then the shutter release button is pressed to the full after changing the framing to the one desired by a user, thus aforesaid problems are solved.
The AF lock system is employed even in a remote-controlled camera, but on a conventional remote-controlled camera, the AF lock is canceled after completion of remote-controlled photographing for one frame. However, remote-controlled several shots under one framing are required in many cases, and in such a case in a conventional remote-controlled camera, a user has been compelled to go to the camera to repeat AF lock operations for each shot. This is very troublesome and it decreases the advantages of the remote-controlled operation that a camera can be operated from a distance.
The second object of the invention devised from aforesaid viewpoint is to provide a camera with which a subject staying at the same position can be photographed easily any number of times on a remote-controlled manner.